The present invention relates to the field of communications, and, more particularly, to phased array antenna systems and related methods.
Antenna systems are widely used in both ground based applications (e.g., cellular antennas) and airborne applications (e.g., airplane or satellite antennas). For example, so-called xe2x80x9csmartxe2x80x9d antenna systems, such as adaptive or phased array antenna systems, combine the outputs of multiple antenna elements with signal processing capabilities to transmit and/or receive communications signals (e.g., microwave signals, RF signals, etc.). As a result, such antenna systems can vary the transmission or reception pattern (i.e., xe2x80x9cbeam shapingxe2x80x9d) or direction (i.e., xe2x80x9cbeam steeringxe2x80x9d) of the communications signals in response to the signal environment to improve performance characteristics.
Several attempts have been made in the prior art to reduce the overall rate at which beam commands (e.g., beam steering commands) are processed and to reduce beam latency times). For example, one particularly useful approach is disclosed in U.S. Pat. No. 5,990,830 to Vail et al. entitled xe2x80x9cSerial Pipelined Phase Weight Generator for Phased Array Antenna Having Subarray Controller Delay Equalization,xe2x80x9d which is assigned to the present assignee. The patent discloses a xe2x80x9cjust in timexe2x80x9d pipelined signal processing architecture for a phased array antenna. Signal propagation paths between a pipelined communications link-through subarray control processors distributed along the pipeline link-and phase control elements of the antenna have different serial pipelined transport delays. These delays are such that all of the phase control signals, after being fully processed by the subarray control processors, are applied simultaneously to their associated subsets of antenna phase control elements. As a result, wiring complexity is reduced and beam steering updates are provided more rapidly.
Another more general prior art approach to improving processing time is disclosed in U.S. Pat. No. 6,023,742 to Ebeling et al. entitled xe2x80x9cReconfigurable Computing Architecture for Providing Pipelined Data Paths.xe2x80x9d This patent discloses an architecture which includes a reconfigurable data path. The data path has a plurality of elements including functional units, registers, and memories whose interconnection and functionality is determined by a combination of static control (i.e., configuration) and dynamic control (i.e., instructions). These elements are connected together, using the static configuration, into a pipelined data path that performs a computation of interest. The dynamic control signals are used to change the operation of a functional unit and the routing of signals between functional units. The static control signals are each provided by a static memory cell that is written to by a host.
While the pipelining functionality of such an architecture may provide certain advantages in some applications, it may not be well suited for application in a phased array antenna system where different types of processing may occur in different controllers (e.g., in a central controller, subarray controllers, and antenna element controllers). That is, while such prior art methods may provide some improved processing time as a result of pipelining within a given processor or level of processors, significant delays may still result when downstream processors remain idle waiting for upstream processors to provide the appropriate beam steering/shaping commands and data.
In view of the foregoing background, it is therefore an object of the present invention to provide a phased array antenna system which provides more efficient usage of processor time and may therefore reduce beam steering latency time and increase beam steering update rates.
This and other objects, features, and advantages in accordance with the present invention are provided by a phased array antenna system which may include a substrate and a plurality of phased array antenna elements carried by the substrate, a plurality of antenna element controllers connected to the phased array antenna elements, and at least one higher level controller connected to the plurality of antenna element controllers. The at least one higher level controller may perform a processing operation on a first portion of a received multi-bit command message before receiving all bits of the multi-bit command message.
More particularly, the at least one higher level controller may transmit downstream results of the processing operation before receiving all bits of the multi-bit command message. The at least one higher level controller may include a plurality of subarray controllers, and each subarray controller may be connected to a respective group of antenna element controllers. Additionally, the phased array antenna system may also include a first serial communications network connecting the subarray controllers to the antenna element controllers.
Furthermore, the at least one higher level controller may further include a central controller connected to the plurality of subarray controllers, and a second serial communications network may connect the central controller to the subarray controllers. Additionally, the phased array antenna system may also include a host connected to the central controller. The multi-bit command message may relate to beam steering, and the processing operation may include a serial multiplication, for example. Also, the first portion of the at least one multi-bit command message may include at least one least significant bit thereof.
A method aspect of the invention is for operating a phased array antenna system such as that described above. The method may include using the at least one higher level controller for performing a processing operation on a first portion of a received multi-bit command message before receiving all bits of the multi-bit command message.